1287121764 has 12 divisors (see below), whose sum is σ = 3003284144. Its totient is φ = 429040584.

The previous prime is 1287121729. The next prime is 1287121783. The reversal of 1287121764 is 4671217821.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53630062 + ... + 53630085.

Almost surely, 2^1287121764 is an apocalyptic number.

It is an amenable number.

1287121764 is an abundant number, since it is smaller than the sum of its proper divisors (1716162380).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1287121764 is a wasteful number, since it uses less digits than its factorization.

1287121764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107260154 (or 107260152 counting only the distinct ones).

The product of its digits is 37632, while the sum is 39.

The square root of 1287121764 is about 35876.4792587010. The cubic root of 1287121764 is about 1087.7770153338. Note that the first 3 decimals are identical.

The spelling of 1287121764 in words is "one billion, two hundred eighty-seven million, one hundred twenty-one thousand, seven hundred sixty-four".